This invention relates to a method for encapsulating a semiconductor diode and more particularly to a method which uses a low temperature alkali free glass for encapsulating diodes, particularly zener diodes.
In the U.S. Pat. No. 3,723,835, there is disclosed a glass composition for the encapsulation of zener diodes which is essentially a 60-70 weight percent lead oxide, 8-12 weight percent borate, 8-15 weight percent silica, 1-8 weight percent alumina, 1-8 weight percent zinc oxide and 1-7% titanium oxide. The composition may include some magnesia. While the composition of this patent has been satisfactory for the purpose of encapsulating semiconductor diodes, a problem is encountered in the discoloration sticking of the encapsulating glass to the graphite boat in which it is held while being sealed.
A major object of this invention is to provide a method for encapsulating semiconductor diodes which includes providing a glass which essentially eliminates the sticking problem while maintaining the other desirable characteristics of the previous glass composition.